Tool-holder.



H. FISH.

TOOL HOLDER. APPLICATION FILED P23351912.

1,056,653. Patented Mar.18,1913.

wil

Haw/0 i /7.

h. is w.

UNITED STATES PATENT ()FFIGE.

HAROLD FISH, 0F STRATFQRD, CONNECTICUT, ASSIGNOR TO THE READY TOOL GOM-TOOL-HOLDER.

Specification of Letters Patent.

Patented Mala-18, 1913.

Application filed February 24, 1912. Serial No. 679,695.

To all whom it may concern:

Be it known that I, HAROLD FISH, citizen of the United States, residingat Stratford, in the county of Fairfield and State of Connecticut, haveinvented certain new and useful Improvements'in Tool-Holders; and

I do hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same.

This invention relates to tool holders and more particularly to thatclass used in connection with lathe and shaper work.

An object of this invention is to provide an improved means of grippinga cutting too-l in a holder so as to prevent chattering of the tool fromdisplacing the walls of the socket adapted to receive said tool holder.

A further object of my invention is to provide a tool of the usualdegree of hardness, so as to cause the same to be tough to stand anyvibration without breaking and a to insert a piece of harder metal inthe walls of the socket formed therein to receive the immediate strainand to distribute said strain uniformly along the lower wall of thesocket.

A further object of my invention is to provide a tool holder of metal ofone degree of hardness and to insert a separate piece of metal of afurther degree of hardness in the bottom of the socket" formed in saidholder, said inserted piece being so shaped as to distribute the strainreceived thereon uniformly, so as to prevent rupturing of the toolholder.

Further objects will be apparent from the following specification,appended claims and drawings, in which,

Figure 1 is a sectional View through the tool holder in the first stageof development for thecomplete article, Fig. 2 is an end elevationthereof, Fig. 3 is a view similar to Fig. lin the second stage, Fig. &is end elevation of Fig. 3, Fig. 5 is view similar to Fig. 1 in finalstage, Fig. 6 is end elevation of Fig. 5.

In the manufacture of tool holders, it is necessary that the bodyportion of the said holder be made of a tough metal so that it may besecurely clamped to carriage and at the same time stand vibration. Afterclamping a tool in the socket formed in such a holder, repeated hardusage of the device cess eventually to become enlarged or perhaps breaksthe metal forming the walls of said recess through its weakest point. Inorder to provide a device which can stand constant usage, it isnecessary that a body portion be provided, which possessescharacteristics of a tough but resilient character and that the portionof the socket which receives the strain should be. provided of hardermetal than the body portion of the holder and that said hardened faceshould be so inserted, that the strain exerted thereon is distributeduniformly over a greater area and in such a way as'to avoid any weakjoints which would cause rupturing of the device.

I'provide a holder comprising the shank l0 and of the usualconfiguration/ of such devices. The forward end of the holder isenlarged and provided with a recess 11 which is internally threaded toreceive the set screw 12. In developing the device from the crude to thefinished form the hole 13 is drilled in the end thereof and at aninclination as shown in the drawings. A plug 14 ofmetal considerablyharder than the body portion of the holder, is then inserted in hole 14;and welded therein, preferably by the usual electrical process. A sec"ond hole 15 is then drilled through the body portion of the holderparallel to the axis of the plug 14, and so positioned therethrough thatthe circumference thereof passes through the plug 14:, removing theupper portion of the plug 14, the circular opening represented by thebore 15 is then changed to a square having walls thereof approximatelytangent to the circumference of the bore and is adapted to receive acutting tool of the common type. By this construction a is evident thatthe said walls of thesdcket are of sufficient thickness to stand thestrain exerted upon the tool, which strain is later exerted on the lowerface of said socket. Then the remaining portion of the plug 14, which inthe finished product is substantially semicircular in cross section,receives the strain from the cutting tool and distributes same over anincreased area and in such a way as to avoid any severe strain fallingonthe side walls of the recess at the junction of that portion below thesocket.

The inserted piece 14 is shown semicircular in section and in this formis best adapted to receive uninjured the shocks attendant upon theoperation of the tool holder and will also have least tendency to crackwhen in this form. However, I do not ICs'llhl myself to the semicircularfOTIIlZlllLll of the inserted piece as said piece may he madenon-circular, such as hexagonal or the like and Having thus described myinvent-ion, I claim:

1. In a tool holder, a body of a desired tenacity having a socket formedtherein, a piece of harder metal inserted and rigidly secured in saidbody as to form a Wall of said socket to receive the strain.

2. In a tool holder, a body portion of the desired tenacity and shapehaving a socket formed therein, a second piece of harder and densermetal Inserted and rigidly se- ,eured in said body portion, saidinserted portio forming a portion of the walls of said socket, a setscrew carried by said body portion and entering the socket. formed insaid body portion opposite to the inserted' and rigidly secured piece.

In testimony whereof I allix my signature 1n presence of two Witnesses.

HAROLD FISH.

Witnesses:

Tues. Fisn,

OLGA A. RWEN.

